RT info:eu-repo/semantics/article
T1 CH4 continuous measurements in the upper Spanish plateau
A1 Sánchez Gómez, María Luisa
A1 García Pérez, María Ángeles
A1 Pérez Bartolomé, Isidro Alberto
A1 Pardo Gómez, Nuria
K1 Methane concentrations
K1 Background levels
K1 Climate change
K1 Diurnal and seasonal cycles
K1 Influence of anthropogenic sources
AB Continuous methane, CH4, concentrationswere measured in a rural area of the upper Spanishplateau from June 2010 to May 2012 by cavity ringdownspectroscopy technique. The results obtained haveproven the local impact of anthropogenic nearbysources on CH4 concentrations, and evidence a significantinfluence on the overall mean, averaged daily andseasonal patterns recorded at the measuring site. Thepositive anomalies in CH4 concentrations, statisticallysignificant at 95 %, in the southeast sector, defined hereas ESE, SE, SSE and S sectors, have been attributed tothe contribution of the Valladolid urban plume and theurban landfill. Based on this finding, CH4 backgroundlevels were associated to the concentrations recorded inthe remaining un-disturbed sectors. CH4 means of theoverall data set, the southeast sector and backgroundsectors yielded average means of 1,894.1, 1,927.9 and1,887.1 ppb, respectively. The diurnal and seasonalpatterns of the overall data set and background concentrationshave shown that CH4 concentrations are mainlydominated by its reaction with OH radicals. Maximumhourly concentrations were reached during night-timeand early morning, 5–7 h, whereas minimum concentrationswere recorded at 16 h. Maximum and minimummonthly means were recorded in January and July,respectively. The diurnal and seasonal amplitudes,namely, peak-to-peak means, of background concentrationswere 25.1 and 48.1 ppb, respectively. These valueswere significantly lower than those obtained for theoverall data set, 42.9 and 58.1 ppb, revealing the significantrole of local influences on CH4 concentrationsdespite the low frequency of southeast winds recordedat the measuring site, 16.9 %.
PB Springer Science+Business Media
SN 0167-6369
YR 2013
FD 2013
LK https://uvadoc.uva.es/handle/10324/65558
UL https://uvadoc.uva.es/handle/10324/65558
LA eng
NO Environ Monit Assess (2014) 186:2823–2834
NO Producción Científica
DS UVaDOC
RD 22-nov-2024